Switching mechanism



Nov. 27, 1923. 1,475,501

F. A. LUNDQUIST SWITCHING MECHANISM Original Filed Sent. 9. 1918 Patented Nov. 27, 1 92 3.

' UNITED STATES PATENT OFFICE.

FRANK A. LUNDQUIST, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO HENRY S. CONRAD, TRUSTEE.

SWITCHING MECHANISM.

Application filed September 9, 1918, Serial No. 253,156. Renewed June 9, 1923.

To all whom it may concern:

Be it known that I, FRANK A. LUNDQUIST, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Switching Mechanism, of which the following is a specification.

My invention relates to switching mechanisms and has for its object improvements in the construction and operation of auto- 'matic telephon exchanges.

The accompanying drawing is a diagram of the switching mechanism, showing the operative parts and some fragments of the frame work.

The wires 1 and 2 connect this switching mechanism with a subscribers local station. This connection may be immediate or through some intervening switching mechanism. It is assumed that at the local station there is the ordinary telephone apparatus including a calling device operable in the ordinary manner. In such an arrangement, when the Subscriber removes his receiver he connects wires 1 and 2 with each other. If the connection to the subscribers station is through an intervening switching mechanism, then that mechanism leaves the wires 1 and 2 connected to the local station with the calling device at that station having wires 1 and 2 connected. Consequently, the first thing that concerns this mechanism is a closing of wires 1 and 2 to each other. This closes a circuit through relay 3, battery X and resistance R. This attracts armature at to close a pair of adjacent contact springs, and also attracts armature 5 to open the normally closed condition of another pair of contact springs.

The present switching mechanism is operated pneumatically and controlled electrically. The pipe 6 is a general supply pipe connected to some source of compressed air. It connects to a casing 7 in which is a valve having a stem 8 projecting out into contact with the armature 4 or an arm thereon. 'The valve isso arranged that it is normally held closed by the pressure in pipe 6, but will be opened by the attraction of armature 1 so to permit compressed air to flow from,

pipe 6 to pipe 9. Th spring 10 serves to hold the armature 1 against the stem 8, but with a force less than enough to open the valve in casing 7. So arrcngeiarmature 4:

above and below.

is quick to be attracted when an impulse flows through relay 3, but is slow to be retracted when the circuit is broken through the relay. Consequently, relay 3 is a slow relay as far as armature at is concerned. Armature 5 has no such connections to modify its operation and consequently relay 3 is a fast relay as far as armature 5 is concerned. 1

The pipe 9 connects to a pneumatic motor 11 which operates to mov a lever 12 on its pivot 13 when the valve in casing 7 is opened .to permit compressed air to flow from pipe '6 to pipe 9. This motor may be of any construction, but as shown it consists of a cylinder movable axially on an inner stationary member. detail in my pending application Serial Number 250,873, filed August 21, *1918. There are several motors of the same kind in this mechanism.

There are also several valves like that in casing 7 and these will hereafter be referred to by numerals applied to the casings. This form of valve is also described in detail in the above mentioned-application. It is also shown in connection with a relay in in pending application Serial Number 244,731, filed July-13, 1918. 1 Parts of the frame work are shown at 14; and 15, and between these is a bridge 16 which serves as a guide for a slide 17. A spring 18 having one end secured to the slide and its other end secured to the frame work serves to normally hold the slide at theleft on guide 16. g

The slide 17 is in the form of a cross, the left hand arm of which has ratchet teeth Pivoted on a pin 19, which is secured to the bridge 16 and extends through slot in the left hand arm of the slide 17, is a lever 20 having pawls 21 and 22 for engaging the teeth on the slide 17, Pivoted at a convenient place to the fram work isalever 23 having extensions which normally engage the tails of pawls 21 and 22 to hold said pawls from engagement with the teeth on slide 17. From thelever 23'to the lever 12 is a rod 24: so arranged that when motor 11 operates to move lever 12 the lever 23 will be withdrawn from pawls 21 and 22 so that said pawls will fall into engagement with the teeth on slide 17. Supported on the frame work is a: motor I have illustrated such a motor in 25 which engages one end of lever to move said lever in one direction on its pivot 19 when compressed air is admitted to said motor. A spring 26 acts to move lever 20 in the opposite direction when air is exhausted from the motor. The motor and spring 26 operate together to vibrate lever 20 and cause pawls 21 and 22 to engage their teeth and move slide 17 to the right.

On the horizontally movable slide 17 is a vertically movable slide 27 having ratchet teeth on opposite sides of the lower part. Bivoted on a pin 29, which is secured to the slide 17 and extends through a slot in the slide 27, is a lever 30 having pawls 31 and 32 for engaging the teeth on the slide 27. Pivoted at a convenient place on the slide 17 is a lever 33 having extensions which normally engage the tails of pawls 31 andv 32 to hold said pawls from engagement with the teeth of the slide 27. Secured to the rod 24 is one end of a bell crank 34, the other end of which is connected to a rod 35 which eX- tends downward and connects to a bail 36 supported in the frame work. The lever has an arm 37 which projects under the bail 36. In normal position the arm 37 engages bail 36 with the result that lever 33 normally holds paWls 31 and 32 from the teeth on slide 37. But when motor 11 operates to move rod 24 so as to tree pawls 21 and 22, the same movement operates through rod 35 to lift bail 36 and tree pawls 31 and 32. A motor 38 and spring 38 operate to vibrate lever 30 in the same way that motor 25 and spring 26 vibrate lever 20.

Pivoted at a convenient place on the Frame work is a disk 39 having a slot 40 and certain indentations in its periphery as shown. A spring 41 normally holds the disk :19 in the position shown against a stop pin 42. A holding pawl 43 is normally held away 'll'OHl the disk 39, but when the motor 11 moves lever 12, the pawl 43 falls to engagement with the disk.

Pivoted at 44 a lever 45 which is held against a motor 45 by a spring 47. Pivoted to the lever 45 is a pawl 48. When compressed air is admitted to the motor 46 to lift the lever 45. the pawl 48 engages the nearest notch in the disk 39. lVhen the air is thereafter exhausted from motor 46. the spring .7 acts to advance the disk 39 till the holding pawl 43 engages the first adjaceiit notch in the disk 39. At the same time the pawl 48 is lifted by reason oi tail 49 sliding on pin 50.

As previously stated, the first thing that comes to this switching mechanism is a cur rent flowing through relay 3. The attraction of armature 4 closes contact springs 53 and 54 to make a circuit for magnet 56. but at the same time the attraction of armature 5 opens springs 51 and 52- so to break the circuit for magnet- 56. In other words, as

long as a current flows through the relay there is no complete circuit for the magnet 56. But when the subscriber at his local station operates his calling device he breaks the connection between wires 1 and 2 and immediately remakes it and he does this one or more times according to whatnumber he is calling. Each time the circuit broken through relay the armature 5 falls back to permit springs 51 and to close, but springs 53 and 54 remain closed because the armature 4 is slow and does not have time to fall back before the circuit is remade through relay Each time the springs 51 and 52 close under these conditions a current flows as follows :-X.5152 53-54 -55-56-X.

Each inpulse through magnet 56 attracts its armature 57 to open valve 58 which is in a branch 59 of pipe 9. The original impulse coming to relay 3 opened valve 7 to permit compressed air to flow from the source to pipe 9, and this valve 7 is held open during the subsequent operations because the armature 4 is slow. I-lence the opening of valve 58 permits compressed air to low to and throu, i pipe 60 to motor 46 and thus raise lever until it is stopped by contact with stop pin 61. In the pipe 60 near the motor 46 is check valve 62 which permits air to [low readily to motor 46 but checks exhaust therefrom so that opening an eX- haust in pipe 60 for a short interval 01"? time does not cause the motor 46 to fall back. The object 0'? check valve is to cause motor 46 to remain in its operated position during pulsations oi? air pressure in pipe (30 due to the openins and clo ot valve 53 caused by the mo cinents of .'mature 57.

A. similar check valve (i3 is connected to motor 11 so that this motor will not be released by rapid pulsations of air in pipe 9.

Connected in a branch of pipe 60 is a valve 64 which is normally held open by a spring 65 acting on a lever 66. From the valve 64 a pipe 67 extends to the motor 25. lVhen the magnet 56 attracts its armature 57 as before described to admit compressed air to pipe 60 part of this air flows through valve 64 and pipe 67 to motor 25 and causes that motor to move lever 20 on its pivot against the action of spring 26. As the pawls 21 and 22 had been previously released by the action of motor 11, the opera tion of motor 25 causes slide 17 to be moved one step or haltstep to the right. When the circuit through magnet 56 is broken, the armature 57 falls back and the valve 58 closes. When the valve closes it not only suits off the supply of compressed air to pipe 60 but opens the exhaust so that spring 26 may move lever 20 in the opposite direction and advance the slide 17 another step or half step to the right. I prefer to con sider each short movement of the slide as a llltl half-step, a whole step being that due to a complete vibration of the lever 20.-

I have just described the eifect of one impulse through the magnet 56 due to the breaking and remaking once of the circuit through the relay 3 by operation of the calling device at the subscribers local station. When the same thing is done a second time at the'local station, the slide 17 will be advanced another full step. The same thin'gwill continue as long as the impulses follow each other at the speed which is normal in the operation of an ordinary calling device. But as soon as there is a pause in the operation, the air in motor 16 will have. time to become exhausted and spring 47 will return lever 15 to its normal position. In so returning, the pawl 48 will advance the disk 39 one step in a contra clockwise direction.

The lever 66 has an arm 68 which engages a notch in disk 39 whensaid disk is in its normal position. When the disk is advanced as described it moves the lever 66 on its pivot so that the valve 64 may close. In this condition, further pulsations of air in the pipe 60 will not reach the motor 25.

In another branch to the pipe 60 is a valve 69, and associated with this is a spring 70,

and lever 71 with arm 72 engaging disk 39.

In normal position the valve 69 isclosed, but when the disk 39 has been advanced one step as described, the arm 72' drops into a notch in the disk 39 and the spring 7 0 opens valve 69 so that compressed air may flow I from pipe 60 to pipe 73 leading to motor 38.

Under these conditions, when a new series of impulses flow through magnet 56 to put pulses inpipe 60, these pulses flow through pipe 73 and operate motor 38 in the same way as previously described for motor 25. The motor 38 and spring 33 vibrate lever so that pawls 31 and 32 move slide 27 upward.

On slide 27 are wipers 74 and 75, and other wipers 7 6 and 77. The wipers 7 6 and 77 are used for making non-interfering conneetions, the nature of which is not involved in the present invention. The wipers 74 and 75 are the wipers which make telephone connections through suitable contact points over which they move These wipers are connected back to the wires 1 and 2as follows :--74t7 879-8081; and 75'82- 8384.85-2. During the time in which the wipers 74 and 75 are moving over contact points, themotor 46 is inoperation and is holding open the contact springs. 79-80 and 83-84 in the connections between the wipers and the wires 1 and 2. As thus held open, noneof the calling impulses which flow over the wires 1 and 2 to operate relay 3 find their way through wipers 7 1 and 75 to the contact'points over which they travel.

When the series of impulses which cause the wipers to move upward come to a stop, the motor 46 falls back to let springs 7 9-80 and 83-84 to close, and also to advance the disk 39 another step. In'this advance the arm 72 is forced out of its notch in said disk and valve 69 is permitted to close.

When the switching mechanism has arrived at the position last described, the local station is connected through to whatever connections are engaged by wipers 74 and 7 5. During talking current remains on relay 3 and air pressure remains on motor 11, but otherwise the apparatus is dead. When the subscriber hangs up his receiver he breaks the circuit for relay 3, whereupon valve 7 closes and motor 11 falls back. This last lifts'pawls 21, 22, 31, 32 and 13 so that the parts engaged thereby may return to normal position.

The motor38 is mounted upon the slide 17, and moves laterally when that slide moves. Consequently the pipe 7 3 is flexible to accommodate such movement.

It is to be observed that the switchingmechanism has two movements, one horizontal and one vertical. Also, that there are other movements, one of which controls the pawls and another of which holds open the connections between wires 1 and 2 and the wipers 7&1 and 7 5 during the time when said wipers are being advanced over contact points. All of these movements, and all others performed by the switching mechanism, are controlled by a single relay, the relay 3. The magnet- 56 is an electrical de vice but it is an operating rather than a controlling device and might be a pneumatic motor instead of a magnet as far as the operation is concerned.

The motors 25 and 38 with their accompanying springs 26 and 38,, are double acting drives for the slides 17 and 27. That is, the

slides are advanced by both movements of the vibrating levers 20 and 30. This gives a nearly continuous movement as distinguished from the jerky movement of the ordinary step by step apparatus. A forward movement due to push on alternately operating .pawls is also superior to anescapement, in that it avoids the pound and consequent, jarincident to the use of an escapement.

What I claim is 1. In a switching.niechanism, wipers, a

source of compressed air, a relay, and means by which electrical impulses flowing thru said relay will cause corresponding pulses from said source to operate said wipers successively in directions perpendicular to each other. i

2. In a switching mechanism, wipers, a

source of compressed air, pneumatic motors for moving said wipers in directions perpendicular to each other, and a relay serving to control the admission of air by pulsations to said motors in succession.

3. In a switching mechanism, wipers, pneumatic motors for moving said. wipers in directions perpendicular to each other, a supply pipe for said motors, and a pneumatically operated disc for connecting said motors successively to said supply pipe.

4. In a switching mechanism, wipers, pneumatic motors for moving said wipers in directions perpendicular to each other, a source of compressed air, a. third motor, and means by which the third motor serves to connect the other two motors successively to said source.

5. In a switching mechanism having movements in a plurality of direct-ions, pneumatically operated devices for giving said mechanism such movements, a relay, and means by which the operations of said relay cause a plurality of operations of said do vices in one direction followed by a plurality of operations in a second direction.

6. In a switching mechanism movable "for variable distances successively in directions perpendicular to each other, pneumatically operated devices for giving the mechanism such movements, a relay serving to control said devices, and means by which the length oi? each movement given the mechanism will be determined by the number of impulses flowing thru said relay.

7. In a switching mechanism, a source of compressed air, two pneumatic motors connected to said source by a common pipe, means by which air is permitted to flow from said source to said pipe by pulsations, and means by which one of said motors responds to said pulsations by a single stroke while the other motor responds by as many strokes as there are pulsations.

8. The combination with a plurality of pneumatic motors, and a source of compressed air. of a relay connected to a distant stat-ion, and devices so arranged that upon a series of electrical impulses flowing thru said. relay air will be admitted from said source to one of said motors to operate it and upon a second series o'l impulses thru said relay air will be admitted from the source to a. second motor to operate it.

9. A relay connected. in an electrical circuit to a distant station, a motor connected to a source of compressed air, and means by which breaking the electrical connection makes the air connection and making the electrical connection breaks the air connection.

10. A magnet, a motor connected to a source of compressed air, a switching mechanism, and means by which electrical impulses thru said magnet are reproduced as air pulsations in said motor to move said mechanism.

11. The combination with a relay provided with electrical connections to a distant station, a source of air pressure, two air valves, and two motors, of means by which upon a series of impulses flowing t-hru said relay one oil? said valves will be held open and the other valve will be opened and closed alternately to permit air to flow to one of said motors, and additional means by which upon a pause occurring in the series of impulses the air connections will be auto matically shifted from the first motor to the second one.

12. The combination with a relay provided with electrical connections to a distant station, a source of air pressure, and two pipes leading to motors, of means by which upon electrical impulses flowing thru said relay air will flow from the source to one of said pipes by constant pressure and to the other of said pipes by pulsations.

13. The combination with a relay pro vided with electrical connections to a distant station, and two air valves, of means by which upon impulses flowing through said relay one of said valves will be held open and the other will be opened and closed alternately.

141-. A motor, a pipe leading :from a source of compressed air to said motor, two valves in said pipe serving to control the supply of air to said motor, means for operating one of said valves rapidly at short intervals, and means for operating the other valve at longer intervals.

15. A motor, a source of compressed air, a magnet having an arn'iature, means by which air is cut from the motor when the armature stands in either of its alternative positions, and means operated. by rapid vibrations of the armature for admitting air to the motor.

16. In an electropneumatic system, a source of compressed air, two motors, a magnet having an arn'lature responsive to electrical impulses flowing through said magnet, pipes and valves connecting the source to said motors but so arranged that air is shut from both motors when the armature stands in retracted position, means by which air flows to one motor when the armature stands in attracted position, and means tor causing air to (low to both motors when said armature vibrates in response to a series of impulses l'lowing through said magnet.

17. In an automatic telephone system, a switch having primary and secondary motions, pneumatic motors, one for producing each of said motions, valves, one for control ling each of said motors and a change-over device for simultaneously closing one of said valves and opening the other valve.

18. In an automatic telephone system, a switch having primary and secondary mo tions, pneumatic motors, one for producing each of said motions, valves, one forcontrolling each of said motors, a change-over de vice for simultaneouslyclosing one of said valves and opening the other and subsequently maintaining both said valves closed.

19. In a telephone system, an automatic switch having wipers, a pneumatic device for moving said wipers, a line leading to said switch normally connected to said wipers, and another pneumatic device operating to disconnect said line from said Wipers while the wipers are .being moved.

20. In an automatic system, an automatic switch having wipers, said Wipers having primary and secondary step by step movements, pneumatic motors, one for producing each of said movements, a line leading to said switch normally connected to said wipers, and a pneumatic device operating to disconnect said line from said Wipers while the wipers are being moved.

21. In a telephone system, an automatic switch having wipers, a pneumatic device for moving said Wipers, a line leading to said switch normally connected to said wipers, and another pneumatic device operating to disconnect said line from said wipers while the wipers are being moved, a source of air connected to both of said devices by a common pipe, means for causing air to flow through said pipe by pulsations, said first device responding by as many strokes as there are pulsations, said second device responding to said pulsations by a single stroke.

22. In the electrically controlled and pneumatically operated mechanisms of a telephone exchange, means for transforming a series of electrical impulses into corresponding series of air pulsations, and mechanism moving devices operated step by step in one direction by said air pulsations.

23. In the electrically controlled and pneumatically operated mechanisms of a telephone exchange, means for transforming a plurality of series of electrical impulses into corresponding plurality of series of air pulsations, and mechanism moving devices operated step by step in directions perpendicular to each other by said air pulsations.

24. A switching mechanism, a pneumatic motor for operating a device serving to con trol the movement of said mechanism in one direction and for operating another device serving to control the movement of said mechanism in another direction, a source of compressed air for operating said motor,

and means for causing the air to flow from said source to said motor in a series of rapid pulsations 25. In a connector switch having primary and secondary movements, primary and secondary air motors for operating the switch, an air distributor having air connections leading to said motors, a source of air pressure, means for connecting said source to said distributor, and means at said distributor for connecting said source successively to said connections for operating said motors.

26. In a connector switch having primary and secondary movements, primary and secondary air motors for operating the switch, an air distributor, said motors having air connections to said distributor, means for delivering a plurality of series of air pulses to said distributor, and means at said distributor for delivering the first of said series of pulses to the connection leading to said primary motor and the second of said series of pulses to the connection leading to the secondary motor.

27. In a connector switch having primary and secondary movements, primary and secondary air motors for operating the switch, an air pipe, means for delivering pulses of air to said pipe, and means for operatively connecting said motors to said pipe in succession.

' FRANK A; nnunooisr. 

